Thorium monoxide

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Thorium monoxide
Names
IUPAC names
Thorium monoxide
Thorium(II) oxide
Identifiers
3D model (JSmol)
  • InChI=1S/O.Th
    Key: OEANRDRPVNMNRM-UHFFFAOYSA-N
  • [Th]=O
Properties
ThO
Molar mass 248.04 g·mol−1
Appearanceblack solid [1]
Structure
face-centered cubic
a = 4.31 Å
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Thorium monoxide (thorium(II) oxide), is the binary oxide of thorium having chemical formula ThO. The covalent bond in this diatomic molecule is highly polar. The effective electric between the two atoms has been calculated to be about 80 gigavolts per centimeter, one of the largest known internal effective electric fields. [2] [3] [4] [5]

Simple combustion of thorium in air produces thorium dioxide. However, laser ablation of thorium in the presence of oxygen gives the monoxide. [6] Additionally, exposure of a thin film of thorium to low-pressure oxygen at medium temperature forms a rapidly growing layer of thorium monoxide under a more-stable surface coating of the dioxide. [7]

At extremely high temperatures, thorium dioxide can convert to the monoxide either by a comproportionation reaction (equilibrium with liquid thorium metal) above 1,850 K (1,580 °C; 2,870 °F) or by simple dissociation (evolution of oxygen) above 2,500 K (2,230 °C; 4,040 °F). [8]

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Thorium dioxide Chemical compound

Thorium dioxide (ThO2), also called thorium(IV) oxide, is a crystalline solid, often white or yellow in colour. Also known as thoria, it is produced mainly as a by-product of lanthanide and uranium production. Thorianite is the name of the mineralogical form of thorium dioxide. It is moderately rare and crystallizes in an isometric system. The melting point of thorium oxide is 3300 °C – the highest of all known oxides. Only a few elements (including tungsten and carbon) and a few compounds (including tantalum carbide) have higher melting points. All thorium compounds, including the dioxide, are radioactive because there are no stable isotopes of thorium.

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3
).

Oxocarbon

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Bromine dioxide Chemical compound

Bromine dioxide is the chemical compound composed of bromine and oxygen with the formula BrO2. It forms unstable yellow to yellow-orange crystals. It was first isolated by R. Schwarz and M. Schmeißer in 1937 and is hypothesized to be important in the atmospheric reaction of bromine with ozone. It is similar to chlorine dioxide, the dioxide of its halogen neighbor one period higher on the periodic table.

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References

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  2. Skripnikov, L. V. (2016-12-07). "Combined 4-component and relativistic pseudopotential study of ThO for the electron electric dipole moment search". The Journal of Chemical Physics. 145 (21): 214301. arXiv: 1610.00994 . doi:10.1063/1.4968229. ISSN   0021-9606. PMID   28799403. S2CID   42337394.
  3. Denis, Malika; Fleig, Timo (2016-12-07). "In search of discrete symmetry violations beyond the standard model: Thorium monoxide reloaded". The Journal of Chemical Physics. 145 (21): 214307. doi:10.1063/1.4968597. ISSN   0021-9606. PMID   28799357.
  4. Skripnikov, L. V.; Petrov, A. N.; Titov, A. V. (2013-12-14). "Communication: Theoretical study of ThO for the electron electric dipole moment search". The Journal of Chemical Physics. 139 (22): 221103. arXiv: 1308.0414 . doi:10.1063/1.4843955. ISSN   0021-9606. PMID   24329049. S2CID   42153944.
  5. "The ACME EDM Experiment". electronedm.org. Retrieved 2018-08-16.
  6. Dewberry, Christopher T.; Etchison, Kerry C.; Cooke, Stephen A. (2007). "The pure rotational spectrum of the actinide-containing compound thorium monoxide". Physical Chemistry Chemical Physics. 9 (35): 4895–4897. Bibcode:2007PCCP....9.4895D. doi:10.1039/B709343H. PMID   17912418.
  7. He, Heming; Majewski, Jaroslaw; Allred, David D.; Wang, Peng; Wen, Xiaodong; Rector, Kirk D. (2017). "Formation of solid thorium monoxide at near-ambient conditions as observed by neutron reflectometry and interpreted by screened hybrid functional calculations". Journal of Nuclear Materials. 487: 288–296. Bibcode:2017JNuM..487..288H. doi: 10.1016/j.jnucmat.2016.12.046 .
  8. Hoch, Michael; Johnston, Herrick L. (1954). "The Reaction Occurring on Thoriated Cathodes". J. Am. Chem. Soc. 76 (19): 4833–4835. doi:10.1021/ja01648a018.